French police are looking into whether Real Madrid striker Karim Benzema played a part in an alleged attempt to extort money from Marseille midfielder Mathieu Valbuena as he is implicated in a blackmail case.

The allegations center around a purported sex tape, a source close to the investigation told AFP.

According to a statement from the Versailles Prosecutor's office Benzema is under investigation for "complicity in blackmailing and participating in criminal association with intent to organize a crime.

Meanwhile Benzema's lawyer Sylvain Cormier has hit out at the media circus that has surrounded his client's appearance in a French court and outlined his confidence that the Real Madrid striker will be cleared of any crime.

Benzema and Valbuena cannot meet until the midfielder has given his version of events to investigators – prompting France boss Didier Deschamps to omit both players from his squad for the upcoming friendlies with Germany and England.

Cormier has no doubt, however, that the 27-year-old will clear his name once all the evidence has been presented.

He told reporters outside the courtroom in Versailles: "He’s absolutely calm. He knows that he’s beyond reproach. I hope the case will be over very soon.

"The investigating magistrate did not give any specific grounds (on why he has been charged). At the end of the day, it's to confirm an investigation is starting against him.

"That’s a notification. It is absolutely not a pre-conviction. We must be really clear about it. I have read a lot of things in the newspapers. I have heard a lot of mistakes in the radio, speaking about a conviction, a confession. Nothing like that ever happened.

The lawyer went on to remind that his client is not guilty until proven otherwise.

"It is regrettable that the presumption of innocence of famous people may have been disregarded.

"This media hype is a pre-sentence. That shouldn’t happen. We shouldn’t learn in the media that we could be summoned by the police. To be welcomed by photographs and media in the police station… I am outraged by that situation," he stated further.

Real Madrid confirmed in an official release that the former Lyon striker has returned to training with full backing from the club.

"Karim Benzema trained at Real Madrid City, where he completed an evening session on his own," read the club's media release.

"The forward, who is still recovering from injury, jogged around the training pitch and carried out various exercises with and without the ball.

"Karim Benzema has given his statement to the French authorities. The president of Real Madrid, Florentino Perez, has held a meeting with the player in which he expressed his full support and belief in his innocence.

"The club is sure of his professionalism, values ​​and commitment which he demonstrated during the six years that he has been part of Real Madrid," the statement affirmed.